This proposal represents a first step in a program of work designed to develop a screening measure to improve early identification of children at risk for severe, persistent or increasing disruptive behavior or attention problems or both (i.e., symptoms of Attention-Deficit/Hyperactivity Disorder [ADHD] and/or Oppositional- Defiant Disorder [ODD]). The primary aim tested is that temperamental traits and cognitive control will differentiate children at risk for severe, persistent or increasing symptoms of disruptive behavior and/or attention problems over one year. Subsidiary aims include: 1) examination of whether temperament trait and cognitive control profiles vary as a function of diagnostic status and 2) evaluation of whether individual differences in temperament traits and cognitive control predict the one-year course of severe preschool disruptive behaviors over and above initial symptom levels. Distinct temperamental and cognitive factors are expected to be associated with each diagnosis and changes in their symptom levels. Children with severe, persistent or increasing attention problems (ADHD) will be characterized by low levels of trait and cognitive control, while children with severe, persistent or increasing oppositional-defiance and hyperactivity-impulsivity (ODD or ADHD+ODD) will be characterized by high levels of negative emotionality and approach. Using a one- year short-term longitudinal design, a sample of 120 children between the ages of three and six will be recruited via newspaper, radio, and posted advertisements until a target of at least 30 children per diagnostic group (i.e., ADHD, ODD, ADHD+ODD, and non-ADHD/ODD) is reached. During the initial in-person assessment, parents will complete a semi-structured diagnostic interview to evaluate children's diagnostic status. Temperament will be measured using the Laboratory Temperament Assessment Battery (observational ratings), the California Q-Sort (examiner ratings), and the Child Behavior Questionnaire (parent ratings). Cognitive control will be measured by having the children complete four tasks: Shape School and Snack Delay will measure response inhibition, Digit Span will measure working memory, and Trails-P will measure set- shifting. At six months and one year following the initial assessment, the diagnostic interview will be conducted with parents again, over the telephone. Analyses will evaluate the utility of incorporating temperament and cognitive control measures with standard diagnostic screening measures to improve prediction of the one-year course of severe preschool disruptive behaviors. This is the first study to comprehensively evaluate whether the short-term course of preschool disruptive behaviors can be predicted by initial status on temperament traits and cognitive control. The current study will evaluate whether the incorporation of temperament and cognitive control assessment into standard diagnostic batteries will enable better prediction of the course of severe disruptive behavior problems, thereby improving the ability to identify children who would benefit most from early intervention. PUBLIC HEALTH RELEVANCE: The current proposal seeks to evaluate temperament and cognitive control as mechanisms of preschool disruptive behaviors (inattention, hyperactivity-impulsivity, and oppositional-defiance;Attention- Deficit/Hyperactivity Disorder and/or Oppositional-Defiant Disorder). The integration of temperament and cognitive mechanisms of preschool disruptive behavior disorders with standard diagnostic assessment procedures may allow for more accurate prediction of the one-year course of disruptive behavior problems and thus more accurately identify those children who would benefit most from early intervention.